At present, there are problems or diseases of the eye in which the progress of the problem is monitored by measuring, from time to time, the size or shape of a visible feature in the eye. An example is the problem of neo-vascularization in which new blood vessels are generated. Other measurements medical personnel might make are of scar tissue, the diameter or cord of a normal cornea, lesions and cysts in various locations, and the like. At the present time, measuring operations of this type are carried out crudely, for the most part, by means of a rigid ruler or the like placed adjacent to the eye. It is clear that such methods of measuring are highly inaccurate and unsatisfactory in medical practice.
The present invention solves the problem described above by providing a contact lens which can be placed directly on the eye, the lens carrying markings or indicia usable for measuring visible features in the eye.